Ellie has been training for the Cedar Ridge Off-Road Race. The first week she trained, she ran 3 days and took the same two routes each day: 2.5 miles on a path in the woods in the morning and a longer route at the park in the afternoon. By the end of the week, Ellie had run a total of 24 miles. Which equation can you use to find how many miles, x, Ellie ran each afternoon?